News and Features
Study Demonstrates Potential Cure for Hepatitis C
A recent long-termstudydemonstrated that use of peginterferon alfa-2a, either alone or in combination with the drug ribavirin, may be a potential cure for Hepatitis C Virus (HCV) infection. To date, no potential cure for HCV has been developed--this study is a landmark in HCV treatment and research.
The study, led by Dr. Mitchell Shiffman of the Virginia Commonwealth University School of Medicine, consisted of 997 individuals either infected with HCV or coinfected with both HCV and HIV. Participants were treated with peginterferon alfa-2a either alone or in combination with ribavirin and were followed for up to seven years. Results of the study showed that 99% of HCV infected individuals treated with peginterferon alfa-2a either alone or in combination with ribavirin had no detectable virus throughout the seven-year follow-up period.
Approximately one-quarter of HIV-infected people in the United States are coinfected with HCV, which is considered an opportunistic infection. HCV is an infectious disease of the liver and is one of the most common causes of chronic liver disease, which progresses more rapidly in people who are coinfected with HIV. As such, an effective cure for HCV would be an important step in reducing mortality in HCV/HIV coinfected patients.
AIDSinfo provides information about HCV/HIV coinfection, including links, fact sheets, and clinical research:
- HCV/HIV coinfection links
- Hepatotoxicity fact sheet
- HCV/HIV coinfection clinical trials
Study Shows Importance of Testing for Antiretroviral Drug Resistance and Viral Tropism
According to a study published in the May 31, 2007 issue of the journal AIDS, acquiring drug resistant strains of HIV is relatively common in men who have sex with men (MSM) who have been recently infected with the virus.
Dr. Susan H. Eshleman's research team collected and analyzed data from 195 MSM in the United States from 1999 to 2003. Samples were collected within 6 months of seroconversion and were tested for HIV-1 subtype, antiretroviral drug resistance, and HIV-1 tropism (i.e., which receptor the virus uses to infect cells). The results show that 100% of the men tested were infected with HIV-1 subtype B, 15.9% had antiretroviral drug resistance, and approximately 2% had CXCR4 tropic strains of the virus. These data show that transmission of antiretroviral drug resistant strains of HIV is a significant problem that must be assessed when designing an antiretroviral treatment regimen.
The additional finding that 3.6% of the men tested had multi-drug class resistance underscores the need to develop new classes of antiretroviral drugs to stay ahead of the rapidly mutating HIV virus.
Maraviroc, an investigational drug in the new entry inhibitor class, is an example of just such a drug. Maraviroc uses the novel mechanism of blocking HIV from binding CCR5, the coreceptor that is used by most strains of HIV to enter immune cells during infection. However, if a person is infected with a CXCR4-using strain, as 2% of the subjects in this study were, maraviroc may not be effective in combating the virus.
Maraviroc was recently recommended for accelerated FDA approval, and the Eshleman study illustrates the importance of HIV-tropism testing prior to the addition of maraviroc to an antiretroviral regimen, if it is approved.